“How did I do?” Julian Castro asked. His identical brother, Joaquin, stood still on the stage by his side with a knowing smile.

The crowd of hundreds at the “Latinos Unidos” party in the vast ballroom of the Charlotte Convention Center roared its approval.

“I’m a much happier, more relieved guy,” said Castro, referring to the relief over having behind him – at last – the much awaited keynote speech of the Democratic National Convention that he’d been tapped to deliver.

The San Antonio mayor, 37, brought the house down at the convention hall. Delegates, those posting on social media, and pundits overwhelmingly praised his talk as heartfelt and charismatic. He evoked images of Barack Obama in 2004, when the then-little known Illinois U.S. Senator riveted delegates and the television audience with his keynote speech at the Democratic National Convention. Talk followed about how he could be a future presidential candidate.

"The story of Latinos in the United States is a story of great faith, of hard work and of good values," Castro told the crowd in the ballroom. He urged them to work their hardest to make sure Obama gets a second term.

"Make the phone calls, send the emails" to build support among Latino voters, he said, as his brother, who did not speak, nodded and smiled in support of his twin.

“He knocked it out of the park, didn’t he?” asked actress Eva Longoria, who appeared briefly on stage at the ballroom to introduce the Castro brothers. Longoria, who is a co-chair of the Obama re-election campaign, said that in her native Texas, the San Antonio mayor’s political prowess and magnetism was known across the state.

“Now, the entire country knows, too,” she said to applause.

And Twitter had a new popular hashtag -- #juliancastro2016.

Matty Lazo-Chadderton, one of a few Latino delegates from North Carolina, sighed when asked about Castro’s speech.

“I cried, tears just ran and ran down my cheeks,” she said. “I’m a single mother, when I listened to his story about how he appreciated his mother, and how she worked for her children’s future, I was moved. He showed you can succeed, you can make it.”

Elizabeth Llorente will be reporting all week from the Democratic National Convention in Charlotte, North Carolina.